‘Tis the season for stagnation. Tri-Cities air quality inching down

The forecast for stagnant air and freezing fog in the Tri-City area has been extended into early next week by the National Weather Service.

An upper level ridge is limiting air movement and is expected to lead to deteriorating air quality.

Thursday monitoring by the Benton County Clean Air Agency continued to show that air quality remained in the range rated as “good,” but it was nearing quality considered just “moderate.”

The air quality advisory is set to expire at noon Tuesday, but could be extended again.

Morning and nighttime fog is expected to persist through at least Wednesday morning.

With temperatures in the 20s at night and the 30s during the day in the Tri-Cities, drivers may encounter freezing fog that makes the roadways slick.

This story was originally published December 7, 2017 at 6:29 PM with the headline "‘Tis the season for stagnation. Tri-Cities air quality inching down."